Method and apparatuses for transmission of data from drill bit in well while drilling

ABSTRACT

A method and several mechanisms for carrying out the method are disclosed. The method of (1) generating torque pulses by engaging and disengaging a torque generator on the lower end of a drill string in the bottom of a wellbore, and (2) monitoring the top of the drill string for the torque pulses therein may be practiced by an inertial wheel detachaby coupled to a drill collar on the lower end of a rotating drill string in a wellbore for being momentarily and precisely coupled and uncoupled during drilling for generation of torque pulses in the drill string for being monitored at the surface. Mechanical, electrical, and fluid operated couplings are disclosed for rapidly braking the rotating inertial wheel.

-Z8==7+ GR 398209389 tinned States Patent 1191 1111 3,820,389 Richter, Jr. et al. June 28, 1974 METHOD AND APPARATUSES FOR TRANSMISSION OF DATA FROM DRILL Primary Examiner-Jerry W. Myracle BET {N WELL WHlLE DRILLING Attorney, Agent, or Firm-Thomas H. Whaley; C. G. [75] Inventors: Ailbert P. Richter, Jr., Houston; Rels K215121111)? ilgxlvlcllvers, Jr., Bellane, 57] ABSTRACT A method and several mechanisms for carrying out [731 New York NY the method are disclosed. The method of l) generat- [22] Filed: Sept. 20, 1972 ing torque pulses by engaging and disengaging a pp No: 290,676 torque generator on t e lower end of a dull string 1n the bottom of a wellbore, and (2) monitoring the top of the drill string for the torque pulses therein may be 52 us. 01. 73/151 practiced by an inertial wheel detachaby coupled to a 51 1111.0 lElZb 47/12 I drillcollaron the lowerend of arotating drill String in 58 Field 01 Search 73/151, 152, 136 R; a wellbore for being momentarily and precisely 175/40 50 230 2 9 pled and uncoupled during drilling for generation of torque pulses in the drill string for being monitored at [56] Ref Cit d the surface. Mechanical, electrical, and fluid operated UNITED STATES PATENTS couplings are disclosed for rapidly braking the rotating 2,775,889 1/1957 Decker 73/151 menial wheel' 3,703,096 11/1972 Vitter, Jr. et al. 73 151 22 Claims, 6 Drawing Figures PRINTED- 1 12 i974 SHEU 1 0f 3 I FIG! PATENTEDJUN 28 I974 METHOD AND APPARATUSES FOR TRANSMISSION OF DATA FROM DRILL BIT IN WELL WHILE DRILLING BACKGROUND OF THE INVENTION While drilling wells, such as wells for the recovery of petroleium from subsurface petroleum containing formations, there are many measurements which are desired by people doing the drilling for determining the lithology being encountered as the wellbore progresses deeper and deeper into the earth. The usual practice today during the drilling of oil and gas wells is to interrupt the drilling operation periodically, to pull the entire drill string from the wellbore, and to run logging tools down into the wellbore for determining the tupes of earth formations which have been penetrated by the wellbore and the characteristics of such formation layers indicative of the presence of petroleium deposits prior to running the entire drill string back into the wellbore. As the well gets deeper and deeper, the time required for the removal and rerunning of this drill string, known in the industry as a trip, becomes greater and greater. Some wells are so deep as to require 24 hours to make a trip, plus many additional hours for the running of a logging tool into the formation. Further it has long been realized that it would be highly desirable to perform certain'basic logging operations during the course of the drilling operation, and to transmit such information back up to the surface either periodically or continually. If thiswere possible, it would permit a complete record of the subsurface lithology to be accumulated as the drilling proceeds and would not necessitate the delay of drilling operations for the running of logs.

Thus it would be very advantageous, during drilling operations of a wellbore, to possess a signal system for the transmission of information from the area of the bottom of the wellbore or the drill bit to the surface using the most convenient continuous communications line available, the drill string, as the communication medium. For many types of information, the signal does not have to be transmitted continuously during drilling but can be transmitted at certain intervals. Ex emplary information that is needed very urgently at the surface during drilling are borehole deviation, information from drilling tests stored in a memory unit or a warning signal, as a pressure difference detected and stored when drilling through a gas zone. Thus during drilling it would be desirous to obtain this information as soon as possible.

While a prior signal transmission system comprises modulation of mud pressure or mud flow by a variable valve in the mud conduit in the bottom of the drill pipe, as in U.S. Pat. Nos. 2,930,137; 3,327,527; or 3,345,867; this system is not reliable due to sticking of the valve because of the solids in the mud and due to failure of the valve because of the abrasion thereof by the mud per se. Another prior but different data transmissions system comprises a controllable wellbore wall engaging means extendable transversely from the sides of the drill stem for momentarily increasing the drag or torque in the drill pipe while rotating the drill pipe for sending torque pulses to the surface through the drill string. This latter system is disclosed in patent application Ser. No. 279,899 filed Aug. ll, 1972, by assignee of record. Others, as in U.S. Pat. No. 3,520,375, have detected the mechanical characteristics of rocks being drilled by comparing the vertical vibrations and axial movement of the drilling assembly for comparison with known rock properties and apparently any resultant torsional accelerations as the drill bits roll over and grind up the rocks.

OBJECTS OF THE INVENTION Accordingly, a primary object of this invention is to provide a reliable method for transmission of data from the bottom of a wellbore to the top while drilling.

Another primary object of this invention is to provide a data transmission system utilizing a rotating torque pulse generator that may be coupled and uncoupled to the drill string for precise interruption of torque forces therein when drilling for transmitting torque pulses for detection at the top of the drill string.

Still another object, of this invention is to provide a data transmission system utilizing a rotating inertial wheel that is coupled and uncoupled to a drill string with a solenoid actuated spring clutch while drilling;

Another object of this invention is to provide a data transmission system utilizing a rotating torque pulse generator that is coupled and uncoupled to a drill string with a magnetic actuated spring clutch while drilling;

Yet another object of this invention is to provide a data transmission system utilizing a rotating inertial wheel that is coupled and uncoupled to a drill string with a fluid operated clutch while drilling;

A still further object of this invention is to provide a data transmission system for continuous transmission of data from a downhole tool while drilling which is easy to operate, is of simple configuration, is economical to build and assemble, and is of greater efficiency for generating signals from a rotating drill bit deep in a well to the surface.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings diagrammatically illustrate by way of example, not by way of limitation, three forms or mechanisms for carrying out the method of the invention wherein like reference numerals have been employed to indicate similar parts in the several views in which:

FIG. 1 is a schematic vertical view of the invention when incorporated in an oil or gas well being drilled;

FIG. 2 is a schematic vertical sectional view of the invention as mounted in a drill collar of the drill string of FIG. 1;

FIGS. 3 and 4 disclose a modification of FIG. 2 having a solenoid operated mechanical catch illustrated schematically in section;

FIG. 5 is another modification of FIG. 2 having an electrically operated clutch illustrated schematically in section; and

FIG. 6 is another modification of FIG. 1 having a fluid operated clutch illustrated schematically in section.

DESCRIPTION OF THE INVENTION The invention disclosed herein, the scope of which being defined in the appended claims, is not limited in its application to the details of construction and arrangements of parts shown and described for carrying out the disclosed method, since the invention is capable of other embodiments for carrying out other methods and of being practiced or carried out in various other ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Further, many modifications and variations of the invention as hereinbefore set forth will occur to those skilled in the art. Therefore, all such modifications and variations which are within the spirit and scope of the invention herein are included and only such limitations should be imposed as are indicated in the appended claims.

DESCRIPTION OF THE METHOD A method is set forth for transmitting data from the bottom of a drill string in a wellbore during drilling thereof to the top of the wellbore comprising the steps of,

l. generating torque pulses by engaging a rotating torque pulse generator in a drill collar on the lower end of the drill string at the bottom of the wellbore, and

2. monitoring the top of the drill string for the torque pulses therein.

For greater details, the first step may comprise:

l. Interrupting the turning of a rotating inertial wheel on a drill string during drilling by momentarily braking the rotating inertial wheel to generate torque pulses in the drill string.

The first step may be modified further as:

l. coupling and uncoupling a rotating inertial wheel on the lower end of a rotating drill string, and

2. controlling the coupling and uncoupling of the rotating inertial wheel to the drill string for generating the precise torque pulses in the drill string.

More details of the second step of the basic method comprise:

l. monitoring the time modulation between the torque pulses in the drill string.

The torque pulses may be either positive or negative.

Further details of the second basic step comprises:

l. monitoring the time modulation of either the length of the time between the pulses, or the number of pulses in the drill string due to interruptions in the drill bit rotation.

DESCRIPTION OF APPARATUSES OR SYSTEMS OF DATA TRANSMISSION FROM A WELLBORE WHILE DRILLING The drawings disclose several embodiments of the invention for carrying out or practicing the above described method for transmitting intelligence from the bottom of a wellbore of conditions at the bottom to the surface, either while drilling is in progress or during a lull in drilling.

FIG. 1 discloses schematically a system for carrying out the basic method of data transmission from a wellbore during drilling operations.

In a drilling rig 10, FIG. 1, a suitable motor 11 drives a rotary table 13 with a sensitive torque meter 12 connected there-between. A drill string 14 in wellbore 15 has a kelly 16 rotated at its upper end by the rotary table 13 and has interconnected therein drill pipes 17, drill collar 18, and a drill bit 19.

EMBODIMENT OF FIG. 2

A feature of the invention is the rotatable torque pulse generators or inertial wheels, as wheel 20 of FIG. 2, controlled by a conventional controller 21 for being coupled and uncoupled or braked while drilling for varying the torque in the drill string for generating torque pulses timed or proportional to the wellbore information desired to be transmitted. These torque variations or torque pulses generated in the lower end of the drill string by the uncoupling and coupling of the rotating inertial wheel 20 from the drill collar 18 in drill string 14 in precisely timed intervals representing well bottom data from the controller 21 are transmitted up through the drill string, through the rotary table 13 to the sensitive torque meter 11 where the data is received. This torque meter is any suitable torque meter, such as but not limited to the Texaco Torque Meter dis closed in US. Pat. No. 3,295,367 by Dr. H. A. Rundell.

While only the one inertial wheel 20, FIG. 2, and its attendant operating parts as a conventional clutch or brake 22, etc., all positioned in the torque pulse generating module 31, FIG. 1, are illustrated for simplicity and clarity of disclosure, several inertial wheels are preferred to be controlled by the single controller 21, FIG. 2.

Controller 21 is a conventional detector of temperature, pressure, weight on the bit, and of other logging parameters such as SP (self potential) or resistivity for operating the clutch 22 off and on for generating torque pulses modulated in proportion to the data transmitted, i.e., time modulated pulse generator, such as but not limited to a conventional logging pulse generator, all positioned in measurement and instrumentation module 30, FIG. 1. Likewise, the controller may incorporate therein any suitable downhole tape recorder system as disclosed in US. Pat. No. 3,566,597.

Torque pulse generator or rotating inertial wheel 20, FIG. 2, is rotatably mounted in bearings 23a and 23b in drill collar 18 and protected from the drilling mud 24 in the center of the drill collar by protective sleeve 25 having seals 25x, 25y. The clutch or brake mechanism 22 having conventional brake shoes similar to automobile wheel brakes is controlled by the controller 21 so that during drilling when the drill string is rotating its normal rpm (revolutions per minute), the clutch 0r brake mechanism may momentarily engage to connect the stopped or slowly idling inertial wheel to the spinning drill collar in a series of engagements to prduce a series of opposite or positve torque forces in the drill collar for detection at the surface by the torque meter. Altemately, the drill string 14, FIG. 1, may be raised off the bottom, as by 20 feet for example, the clutch mechanism 22, FIG. 2, engaged to rotate the inertial wheel 20 therewith, the clutch disengaged prior to stopping the drill string, and then with the drill string hanging still, the clutch is engaged momentarily to generate a negative torque pulse in the drill string in the same direction of rotation for drilling.

Thus in the embodiment of FIG. 2, the stopped or slowly idling inertial wheel is either suddenly engaged with the spinning drill collar to generate a positive torque pulse in the drill string 14, or the drill collar and the inertial wheel is spun up to drilling speed, the spinning inertial wheel then is disconnected from the drill collar, the drill collar stopped, and then the clutch 22 momentarily engaged to generate a negative torque pulse in the drill string 14.

The embodiment of FIG. 2 has a further device thereon, a conventional motor-generator device 26 connected between the drill collar 18 and the inertial wheel with a stator on one element, as on the drill collar 18 and a rotor on the other element, as the inertial wheel 20. In operation, with several inertial wheels and motor-generators, some are connected with conventional electrical connections to generate electricity for storage thereof at the controller with relative move-' ment between the inertial wheels and the drill collar, and other motor-generators are connected with conventional electrical connections to the controller for reversing the current flow tending to reverse rotation for generating torque pulses in the drill string.

Further, the embodiment of FIG. 2 may be operated by the controller 21 for precisely controlling the individual braking of at least two inertial wheels for generating two torque pulses with the time therebetween being relative to, or equal to a function of, the measured parameter, as temperature of the formation, for example. This is another example of how controller 21 is used as a time modulated pulse generator.

MODIFICATION OF FIGS. 3 and 4 FIG. 3, a vertical sectional view at 3-3 on FIG. 4 of another embodiment of the invention and FIG. 4, a horizontal sectional view of the embodiment of FIG. 3; disclose an electo-mechanical catch or brake 22a for quickly engaging and disengaging one of the rotating inertial wheels 20a protected by shield 25a. Like the embodiment of FIG. 2, several inertial wheels are mounted either in tandem or concentrically with each other in the drill collar 18a of FIG. 3, each having a solenoid operated brake having a brake arm 27 which is normally held in retracted, uncoupled, inactive position by tension spring 28. Ann 27, which is pivotally mounted in drill collar ll8a with pin 29 is operable inwardly by a solenoid 32 secured between the arm and the drill collar to ride in tapered groove 33 in the outer surface of the inertial wheel 20a to engage the abuttment 34 to suddenly accelerate the inertial wheel instantly to the same speed as the drill string. This practically instantaneous acceleration of the inertial wheel generates a positive torque pulse in the drill string for detection and recording on the surface by the torque meter 12, FIG. ll, disclosed above. A controller (not shown) similar to that of FIG. 2 is mounted in drill collar llfia.

In operation of the modification of FIGS. 3 and 4, after raising the drill bit off the bottom and rotation stopped, the drill string, including the drill collar, is spun up or rotated to the desired rpm with the catch disengaged. Then at the proper preset time, the catch for each of the several inertial wheels is engaged at the precise moment to transmit the coded torque pulses to the surface torque meter for transmission of live information or information that has been stored in the controller for transmission when called for. For additional transmission of data, the drill string is stopped, the brake disengaged, the drill string spun up to the desired speed, and the brakes engaged in sequence again as dictated and controlled by the controller. This procedure may be repeated as often as required to obtain the information desired. In fact this procedure may be carried out while drilling, but with a decrease in signal strength.

Obviously other methods may be utilized for transmission of signals with the embodiments of either FIG. 2 or FIG. 4 than those listed above, depending on the particular information desired to be transmitted.

MODIFICATION OF FIG. 5

FIG. 5 discloses another modification of the embodiment of FIG. 2 wherein a magnetic clutch or brake 22b is substituted for the brake 22 of FIG. 2. Inertial wheel 20b, one of several inertial wheels, protected from the drilling mud 24 by cylindrical shield 25b, is rotatably mounted in drill collar 18b similar to the embodiment of FIG. 2. Inertial wheel 20b has annular flanges 35 and 36 integral therewith and surrounded by a suitable magnetic particle fluid or powder 37 which is solidified by an electrical coil 38 controlled by a controller similar to that of FIG. 2.

In operation of the magnetic particle brake operated inertial wheel 2% of FIG. 5, with the magnetic particles declutched and lying loosely, the drill collar is spun up to the desired high speed. Then at the preselected time, the clutch or brake 22b is engaged or solidified momentarily to suddenly engage the inertial wheels in precise succession to generate torque pulses up the drill string to the torque meter 12, FIG. 1, for transmission of data from the area of the bottom of the well to the top in an efficient manner. Likewise, this modification may be operated in various methods as suggested for the modifications of FIGS. 2 and 4.

MODIFICATION OF FIG. 6

FIG. 6 illustrates another modification of the rotating torque pulse generator of FIG. 2 in the form of hydraulic brakes 22c for stopping the inertial wheels 200 for generating precisely timed torque pulses in the drill collar 180, FIG. 6, of the drill string. The inertial wheel 20c illustrated has an annular flange 40 integral with the outer surface thereof for operating with the two hydraulic brakes 22c. Each brake comprises a piston 41 operable in a cylinder 42 connected with a high pressure hydraulic fluid line 43 to a suitable controller (not shown) similar to controller 21 of FIG. 2. Piston 41 has conventional sealing O-rings 44, a friction wear pad or surface 45 on the outer end of the piston for pressing against the top side of flange 40, and a tension spring 46 connected between the inner end of the piston and the cylinder for maintaining the brakes free and unlocked when the hydraulic lines are unpressurized. The hydraulic brakes 220 for working against the lower side of the flange 40 is similar to that above, shield 25c protecting the inertial wheel 20c from the mud 24 internally of the drill string.

Thus in operation of the hydraulic brakes 220 of FIG. 6, with the hydraulic pressure line depressurized, the drill collar is spun up to the desired speed. At the preselected time, the hydraulic brakes 220 are actuated or pressurized to momentarily suddenly engage the friction pads 45 with both sides of flange 40 of each of the inertial wheels to generate torque pulses up the drill string to the torque meter at the surface for transmission of data from the bottom of the well to the top. Likewise, this modification may be operated in the various other methods set forth in regard to the operation of the modifications of FIG. 2 and FIG. 4.

In the latter torque pulse generators of FIGS. 4, 5, and 6, while it is preferred that a motor-generator like 26 of the embodiment of FIG. 2 be utilized to power the controllers and instruments in each, storage batteries may be used if so desired.

Accordingly, it will be seen that while drilling is in progress, the disclosed method and several data transmission systems will transmit information from the bottom of a wellbore to the surface and will operate in a manner which meets each of the objects set forth hereinbefore.

While only one method of the invention and several mechanisms for carrying out the method have been disclosed, it will be evident that various other methods and modifications are possible in the arrangement and construction of the disclosed method and data transmission systems without departing from the scope of the invention and it is accordingly desired to comprehend within the purview of this invention suchmodifications as may be considered to fall within the scope of the appended claims.

We claim:

ll. A method for transmitting data from the bottom of a drill string in a wellbore during drilling thereof to the top of the drill string comprising the steps of,

a. generating data by making desired measurements near the bottom of the wellbore,

b. generating torque pulses relative to said data by engaging and disengaging a rotating torque pulse generator in a drill collar on the lower end of the drill string, and

c. monitoring the top of the drill string for the torque pulses therein.

2. A method as recited in claim ll wherein the second step comprises,

a. coupling and uncoupling a rotating inertial wheel on the lower end of the rotating drill string for generating the torque pulses in the drill string.

3. A method as recited in claim 1 wherein the second step comprises,

a. coupling and uncoupling a rotating inertial wheel in a drill collar on the lower end of the rotating drill string, and

b. controlling the coupling and uncoupling of the inertial wheel to the drill string for generating the torque pulses in the drill string.

4. A method as recited in claim 1 wherein the third step comprises,

a. time modulating the torque pulses, and

b. monitoring the time modulation of the torque pulses in the drill string from the drill bit.

5. A method for transmitting data from a drill collar connecting a drill bit on the bottom of a drill string in a wellbore during drilling thereof to the top of the drill string comprising the steps of,

a. generating data by making desired measurements near the bottom of the wellbore,

b. interrupting the turning of a rotating inertial wheel in the drill collar during drilling to generate torque pulses proportional to said data in the drill string, and

c. monitoring the torque pulses in the top of the drill string.

6. A method as recited in claim 5 wherein the second step comprises,

a. coupling and uncoupling the rotating inertial wheel on the lower end of the rotating drill string for generating the torque pulses proportional to said data in the drill string.

7. A method as recited in claim 5 wherein the third step comprises,

a. time modulating the torque pulses, and

b. monitoring the time modulation of the torque pulses in the drill string due to interruptions in the drill bit rotation.

8. A method as recited in claim 5 wherein the second 5 method step comprises the two steps of,

a. interrupting drilling by raising the drill bit off the bottom of the wellbore, and

b. interrupting the turning of the rotating inertial wheel by momentarily braking the rotating inertial wheel to generate torque pulses proportional to said data in the drill string.

9. A system for transmission of data from the lower end of a drill string in a wellbore during drilling to the top of the wellbore comprising,

a. a drill string,

b. means on the lower end of said drill string for making preselected measurements to generate data,

c. rotating inertial wheel torque pulse generating means on the lower end of said drill string for generating torque pulses relative to said data in said drill string, and

d. monitoring means on the upper end of said drill string for monitoring said drill bit torque pulses in said drill string.

10. A system as recited in claim 9 wherein the rotating inertial wheel torque pulse generating means comprises,

a. rotating inertial wheel means on the lower end of said drill string, and

b. controllable coupling means between said rotating inertial wheel means and said drill string for controlled coupling and uncoupling of said rotating inertial wheel means from said drill string for generating the drill bit torque pulses proportional to said 35 data.

11. A system as recited in claim 9 wherein the rotating inertial wheel torque pulse generating means comprises,

a. controllable coupling means between said rotating inertialwheel means and said drill string,

b. control means responsive to said preselected measurement means for said controllable coupling means, and

c. said coupling means being responsive to said control means for controlled coupling and uncoupling of said rotating inertial wheel means from said drill string for generating said rotating inertial wheel torque pulses proportional to said data.

12. A system as recited in claim 9 wherein,

a. said rotating inertial wheel torque pulse generating means is mounted in a drill collar connected to said lower end of said drill string between said drill string and a drill bit.

13. A system as recited in claim 9 wherein,

a. means for time modulating said torque pulses, and

c. torque applying means for rotating said drill string means,

d. rotating inertial wheel means for the lower end of said drill string means for applying opposite torque to said rotating drill string for generating torque pulses,

e. controllable coupling means between said rotating inertial wheel means and said drill string means responsive to said preselected measurement means for time modulating said torque pulses,

f. torque monitoring means at the upper end of said drill string means, and

g. said torque monitoring means being responsive to said control means for monitoring the time modulation of said opposite torque pulses in said drill string means from said rotating inertial wheel means.

15. A data transmission system as recited in claim 14 wherein,

a. said controllable coupling means comprises a magnetic controllable coupling means for being activated and deactivated for coupling and uncoupling said rotating inertial wheel means.

16. A data transmission system as recited in claim 14 wherein,

a. said controllable coupling means is a fluid coupling device connected between said rotating inertial wheel means and said drill string means.

17. A data transmission system as recited in claim 14 wherein,

a. said controllable coupling means is a mechanical coupling device connected between said rotating inertial wheel means and said drill string means, and

b. a solenoid actuator for being activated and deactivated for operating said mechanical coupling device.

18. A data transmission system for monitoring wellbore drilling comprising,

a. a drill string for extending into a wellbore for drilling thereof,

b. means on the lower end of said drill string for making preselected measurements to generate data,

c. torque applying means connected to the top of said drill string for applying a torque to the drill string for rotating it in one direction,

d. a rotating inertial wheel in said drill string for applying an opposite torque to said rotating drill string for generating an opposite torque pulse in said drill string,

e. a controllable coupling connected between said rotating inertial wheel and said drill string,

f. a control connected to said controllable coupling for coupling and uncoupling said rotating inertial wheel from said drill string for generating time modulated opposite torque pulses proportional to said data in said drill string, and

g. torque monitoring means connected to the upper end of said drill string for monitoring the time modulation of said opposite torque pulses in said drill string from said rotating inertial wheel.

19. A data transmission system as recited in claim 18 wherein,

a. said controllable coupling is a fluid actuated coupling device connected between said rotating inertial wheel and said lower end of said drill string.

20. A data transmission system as recited in claim 18 wherein,

a. said controllable coupling is a solenoid actuated coupling device connected between said rotating inertial wheel and said lower end of said drill string.

21. A data transmission system as recited in claim 18 wherein,

a. said controllable coupling is an electrically actuated coupling device connected between said rotating inertial wheel and said lower end of said drill string.

22. A data transmission system for monitoring wellbore drilling conprising,

a. a drill string for extending into a wellbore for drilling thereof,

b. means on the lower end of said drill string for making preselected measurements to generate data,

0. torque applying means connected to the top of said drill string for applying a torque to the drill string for rotating it in one direction,

d. a rotating inertial wheel in a drill collar in said drill string for applying an added torque in the same direction to said rotating drill string for generating torque pulse in said drill string,

e. a controllable coupling connected between said rotating inertial wheel and said drill string,

f. a control connected to said controllable coupling for coupling and uncoupling said rotating inertial wheel from said drill string for generating time modulated torque pulses in said drill string relative to said data, and

g. torque monitoring means connected to the upper end of said drill string for monitoring the time modulation of said torque pulses in said drill string from said rotating inertial wheel. 

1. A method for transmitting data from the bottom of a drill string in a wellbore during drilling thereof to the top of the drill string comprising the steps of, a. generating data by making desired measurements near the bottom of the wellbore, b. generating torque pulses relative to said data by engaging and disengaging a rotating torque pulse generator in a drill collar on the lower end of the drill string, and c. monitoring the top of the drill string for the torque pulses therein.
 2. A method as recited in claim 1 wherein the second step comprises, a. coupling and uncoupling a rotating inertial wheel on the lower end of the rotating drill string for generating the torque pulses in the drill string.
 3. A method as recited in claim 1 wherein the second step comprises, a. coupling and uncoupling a rotating inertial wheel in a drill collar on the lower end of the rotating drill string, and b. controlling the coupling and uncoupling of the inertial wheel to the drill string for generating the torque pulses in the drill string.
 4. A method as recited in claim 1 wherein the third step comprises, a. time modulating the torque pulses, and b. monitoring the time modulation of the torque pulses in the drill string from the drill bit.
 5. A method for transmitting data from a drill collar connecting a drill bit on the bottom of a drill string in a wellbore during drilling thereof to the top of the drill string comprising the steps of, a. generating data by making desired measurements near the bottom of the wellbore, b. interrupting the turning of a rotating inertial wheel in the drill collar during drilling to generate torque pulses proportional to said data in the drill string, and c. monitoring the torque pulses in the top of the drill string.
 6. A method as recited in claim 5 wherein the second step comprises, a. coupling and uncoupliNg the rotating inertial wheel on the lower end of the rotating drill string for generating the torque pulses proportional to said data in the drill string.
 7. A method as recited in claim 5 wherein the third step comprises, a. time modulating the torque pulses, and b. monitoring the time modulation of the torque pulses in the drill string due to interruptions in the drill bit rotation.
 8. A method as recited in claim 5 wherein the second method step comprises the two steps of, a. interrupting drilling by raising the drill bit off the bottom of the wellbore, and b. interrupting the turning of the rotating inertial wheel by momentarily braking the rotating inertial wheel to generate torque pulses proportional to said data in the drill string.
 9. A system for transmission of data from the lower end of a drill string in a wellbore during drilling to the top of the wellbore comprising, a. a drill string, b. means on the lower end of said drill string for making preselected measurements to generate data, c. rotating inertial wheel torque pulse generating means on the lower end of said drill string for generating torque pulses relative to said data in said drill string, and d. monitoring means on the upper end of said drill string for monitoring said drill bit torque pulses in said drill string.
 10. A system as recited in claim 9 wherein the rotating inertial wheel torque pulse generating means comprises, a. rotating inertial wheel means on the lower end of said drill string, and b. controllable coupling means between said rotating inertial wheel means and said drill string for controlled coupling and uncoupling of said rotating inertial wheel means from said drill string for generating the drill bit torque pulses proportional to said data.
 11. A system as recited in claim 9 wherein the rotating inertial wheel torque pulse generating means comprises, a. controllable coupling means between said rotating inertial wheel means and said drill string, b. control means responsive to said preselected measurement means for said controllable coupling means, and c. said coupling means being responsive to said control means for controlled coupling and uncoupling of said rotating inertial wheel means from said drill string for generating said rotating inertial wheel torque pulses proportional to said data.
 12. A system as recited in claim 9 wherein, a. said rotating inertial wheel torque pulse generating means is mounted in a drill collar connected to said lower end of said drill string between said drill string and a drill bit.
 13. A system as recited in claim 9 wherein, a. means for time modulating said torque pulses, and b. said monitoring means is responsive to said rotating inertial wheel torque pulse generating means for monitoring the time modulation of said rotating inertial wheel torque pulses in said drill string.
 14. A data transmission system for monitoring wellbore drilling comprising, a. drill string means for the wellbore having a lower end and an upper end, b. means on said drill string means lower end for making preselected measurements to generate data, c. torque applying means for rotating said drill string means, d. rotating inertial wheel means for the lower end of said drill string means for applying opposite torque to said rotating drill string for generating torque pulses, e. controllable coupling means between said rotating inertial wheel means and said drill string means responsive to said preselected measurement means for time modulating said torque pulses, f. torque monitoring means at the upper end of said drill string means, and g. said torque monitoring means being responsive to said control means for monitoring the time modulation of said opposite torque pulses in said drill string means from said rotating inertial wheel means.
 15. A data transmission system as recited in claim 14 wherein, a. said controllable coupling means comprises a magnetic controllable coupling means for being activated and deactivated for coupling and uncoupling said rotating inertial wheel means.
 16. A data transmission system as recited in claim 14 wherein, a. said controllable coupling means is a fluid coupling device connected between said rotating inertial wheel means and said drill string means.
 17. A data transmission system as recited in claim 14 wherein, a. said controllable coupling means is a mechanical coupling device connected between said rotating inertial wheel means and said drill string means, and b. a solenoid actuator for being activated and deactivated for operating said mechanical coupling device.
 18. A data transmission system for monitoring wellbore drilling comprising, a. a drill string for extending into a wellbore for drilling thereof, b. means on the lower end of said drill string for making preselected measurements to generate data, c. torque applying means connected to the top of said drill string for applying a torque to the drill string for rotating it in one direction, d. a rotating inertial wheel in said drill string for applying an opposite torque to said rotating drill string for generating an opposite torque pulse in said drill string, e. a controllable coupling connected between said rotating inertial wheel and said drill string, f. a control connected to said controllable coupling for coupling and uncoupling said rotating inertial wheel from said drill string for generating time modulated opposite torque pulses proportional to said data in said drill string, and g. torque monitoring means connected to the upper end of said drill string for monitoring the time modulation of said opposite torque pulses in said drill string from said rotating inertial wheel.
 19. A data transmission system as recited in claim 18 wherein, a. said controllable coupling is a fluid actuated coupling device connected between said rotating inertial wheel and said lower end of said drill string.
 20. A data transmission system as recited in claim 18 wherein, a. said controllable coupling is a solenoid actuated coupling device connected between said rotating inertial wheel and said lower end of said drill string.
 21. A data transmission system as recited in claim 18 wherein, a. said controllable coupling is an electrically actuated coupling device connected between said rotating inertial wheel and said lower end of said drill string.
 22. A data transmission system for monitoring wellbore drilling conprising, a. a drill string for extending into a wellbore for drilling thereof, b. means on the lower end of said drill string for making preselected measurements to generate data, c. torque applying means connected to the top of said drill string for applying a torque to the drill string for rotating it in one direction, d. a rotating inertial wheel in a drill collar in said drill string for applying an added torque in the same direction to said rotating drill string for generating torque pulse in said drill string, e. a controllable coupling connected between said rotating inertial wheel and said drill string, f. a control connected to said controllable coupling for coupling and uncoupling said rotating inertial wheel from said drill string for generating time modulated torque pulses in said drill string relative to said data, and g. torque monitoring means connected to the upper end of said drill string for monitoring the time modulation of said torque pulses in said drill string from said rotating inertial wheel. 